If you're Conservation Colorado, Polis walks on the water he's helping purify (he gets a perfect 100 percent) and Tipton is covered in mud (he gets an 11), according to its National Environmental Scorecard. Americans for Prosperity gave Tipton a B and Polis a D-.

"The best that can be said about this session of the 112th Congress is that it's over," said League of Conservation Voters President Gene Karpinski.

The two organizations released their latest congressional scorecards for the 112th Congress.

Americans for Prosperity-Colorado calls itself "a free-market grassroots organization." The group says it values "smaller government and economic freedom."

"Colorado constituents need to know how their representative or senator voted," said AFP-CO policy director Sean Paige. "The AFP Scorecard is the best way for our activists to keep a close eye on Washington, and confront them when they don't vote responsibly."

Conservation Colorado has a different perspective on who's being attacked and protected.

"In the face of unprecedented attacks from corporate polluters and their allies in Congress, environmental allies like Senators Bennet and Udall stood up for our values and put Coloradans first," said Conservation Colorado Executive Director Pete Maysmith.

Conservation Colorado's 2012 scorecard includes 14 Senate votes and 35 House votes on issues ranging from public health protections to clean energy to land and wildlife conservation.

Colorado Conservation gave the state's House delegation an average score, in 2012, of 45 percent. The two Democratic Senators averaged 97 percent.

Americans for Prosperity insists the 112th Congress scorecard must include votes on issues such as repealing Obamacare, pre-empting the EPA's purported authority to regulate greenhouse gases, passing Rep. Paul Ryan's budget, ending ethanol subsidies, several Congressional Review Act resolutions to overturn new regulations, and the fiscal year 2012 appropriations bills.